JPH0529799B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a small fan using a piezoelectric vibrator, which is used for ventilation near temperature and humidity sensors in gases, cooling small electronic components, blowing air to deodorizers inside refrigerators, etc. In particular, it concerns a small fan that can be driven by either 50Hz or 60Hz commercial power supply. [Prior art] This type of small fan has a piezoelectric vibrator with a
A small fan consisting of metal vibrating blades made of copper, stainless steel, etc. that resonate at Hz and 60Hz, respectively.
(No.), and a small fan (Japanese Patent Application No. 60-40708, provided by the present applicant), which is equipped with a vibrating vane plate made of synthetic resin that is lightweight and has a high modulus of elasticity. [Problems to be Solved by the Invention] In any of the conventional small fans mentioned above, the relationship between the resonant frequency f ₀ of the vibrating vane plate, the plate length l, the plate thickness t, the Young's modulus E of the plate material, and the density ρ of the plate material is When shown, Therefore, when the frequency of the drive power source changes, the piezoelectric vibrator and the vibrating vane plate can no longer resonate. Even if it is designed to provide maximum airflow under certain conditions,
There is a problem that a satisfactory air volume cannot be obtained if the area of use is different. [Summary of the Invention] In order to solve the above problems, the small fan of the present invention fixes one end of the piezoelectric vibrator 1 to a support part as shown in the first and second figures, and fixes the other end of the piezoelectric vibrator 1 to a supporting part. A plurality of displacement amplifying vibrating vanes 13a and 13b are installed side by side in the displacement amplifying vibrating vane plate 13.
Vibrating blade plates 15a, 15b are installed at the tips of a, 13b.
The present invention provides a small fan in which each vibrating blade plate has a different resonance frequency. In this way, the vibration blade plates 13a, 13 for increasing displacement
When driving with a 50Hz commercial power source by combining the vibrating vane plates 15a and 15b, originally only one vibrating vane plate 15a side would operate at a power frequency of 50Hz.
Hz, but the other vibrating blade plate 1
5b as well, the displacement amplifying vibrating blade plate 13b is synchronized with 50
Shows vibration close to Hz resonance. Similarly, when driven by a 60Hz commercial power supply, the opposite phenomenon occurs. That is, two sets of vibrating blade plates 13a, 15a and 13b, 15
b interfere with each other, one vibrating blade plate 15a
Or when the vibration blade plate 15b resonates, the other vibrating blade plate 15b
Alternatively, 15a swings in sync with this, so by using just one piezoelectric vibrator 1, you can obtain almost the same performance as a combination of two small fans dedicated to 50Hz and 60Hz, making it small, lightweight, and inexpensive. . In addition, compared to the conventional 50Hz and 60Hz dual-purpose type, one vibrating blade only needs to satisfy half the frequency range of the conventional one, so an ideal air volume close to resonance can always be obtained, and frequency dependence is reduced. becomes smaller,
As a result, even if the temperature changes and the resonant frequency changes, according to the above equation (1), performance changes such as air volume are very small, and the operating temperature range is widened. Furthermore, since the displacement amplifying vibrating vanes 13a and 13b play a driving role similar to that of a piezoelectric vibrator, the displacement of the tip of the piezoelectric vibrator 1 itself may be small, so that there is almost no damage to the piezoelectric vibrator 1. [Detailed Description of the Invention] Fig. 1 is a front view showing an embodiment of the small fan of the present invention, and Fig. 2 is a side view thereof. First, its configuration will be explained. In the drawing, 1 is a small, thin piezoelectric vibrator.
For example, length 20~40mm, width 10~40mm, thickness 0.2~0.8
It is of mm size. The piezoelectric vibrator 1 may be a single-layer type made of a ceramic or organic film-like piezoelectric material with film-like electrodes provided on both sides.
As shown in the figure, two film-like piezoelectric materials 9, 9 are pasted together,
In order to obtain large vibrations, it is preferable to use a laminated type (bimorph type) in which membrane electrodes 3 and 4 are provided on the bonding surface and both surfaces. An elastic material 11 such as silicone rubber is pasted on both sides of one end of this piezoelectric vibrator 1, and the one end is fitted into a groove in a fixing base made of two support members 10 made of vinyl chloride, etc., and these are glued together to vibrate the piezoelectric vibrator. Two vibrating blade plates 1 made of metal with a high elastic modulus are connected to the other end of the child 1 via a connecting member 12 made of vinyl chloride or the like.
3a and 13b, and connect the connecting member 1 made of vinyl chloride or the like to each displacement amplifying vibrating blade plate 13a, 13b.
Vibration vanes 15a and 15b made of lightweight synthetic resin with high elasticity are attached via 4a and 14b,
When the total length of one set of vibrating blade plates 13a, 15a and the total length of the other set of vibrating blade plates 13b, 15b are installed individually, the structure is such that the length resonates at a power frequency of around 50 Hz and around 60 Hz. . As the material of the displacement amplifying vibrating blade plates 13a and 13b, metals such as copper, stainless steel, etc. can be used. In addition, the materials of the vibrating blade plates 15a and 15b include 6 nylon, 66 nylon, displacement PPO, ABS,
polyacetal, polyethylene terephthalate,
Synthetic resins such as polyetheretherkent and polypropylene can be used. Further, it may be one in which an inorganic filler, glass fiber, etc. are added to these resins. Specific gravity is 0.9~2.0, elastic modulus is 20000~40000Kg/ ^cm2
is preferred. Next, its effect will be explained. 50Hz or 60Hz between electrodes 3 and 4 of piezoelectric vibrator 1
When a commercial power source is connected and an AC voltage is applied, the piezoelectric vibrator 1 vibrates, and the displacement amplifying vibrating vanes 13a and 13b attached to it vibrate. The other vibrating vane plate 13b or 13a also vibrates as if resonating via the connecting member 12. Further, the vibrating blade plates 15a and 15b attached thereto vibrate. Vibrating blade plates 15a and 15
The relationship between the resonant frequency f ₀ of a, the plate length l, the plate thickness t, the Young's modulus E of the plate material, and the density ρ of the plate material is shown in (1) above.
It becomes as shown in the formula. If the vibrating vanes 15a and 15b are made of synthetic resin that is lightweight and has a high elastic modulus, they will match the mechanical impedance of the piezoelectric vibrator 1 even if driven by either 50Hz or 60Hz commercial power source. Vibrating blade plates 13a and 13 for increasing displacement with expanded vibrations
The vibration energy of b is transferred to the vibrating blade plates 15a and 15
b can be transmitted without waste, and the vibrating vane plate 15
Air can be efficiently blown by appropriately bending a and 15b. In addition, when one vibrating blade plate 15a or 15b resonates, the other vibrating blade plate 15b or 15a can vibrate in synchrony with the resonance, so that the conventional 50Hz and 60Hz
Compared to the dual-purpose type, ideal air volume close to resonance is always obtained, frequency dependence is extremely small, and the above-mentioned
Equation (1) shows that even if the resonant frequency changes due to temperature changes, the changes in performance such as air volume are very small, which widens the operating temperature range and expands the field of application. Table 1 shows the results of determining the air volume when the temperature was changed so that the maximum air volume was obtained at 15° C. for Examples A and B and Comparative Examples a to c. The dimensions of the piezoelectric vibrators in Examples A and B are as shown in Figures 1 and 2, respectively: length L = 25 mm x width W = 30
mm×thickness T=0.6mm, L=25mm×W=40mm×T=
0.6mm, vibrating blade plates 13a, 13 for displacement expansion
The size of b is plate length l′ _a = 15mm, l′ _b = 11mm x plate width
Using a phosphor bronze plate with w′ = 10 mm x plate thickness t′ = 0.2 mm,
In the case of Example A, the size of the vibrating blade plates 15a and 15b is as follows: plate length l = 30 mm x plate width w = 20 mm x plate thickness t =
0.2mm, in the case of Example B, plate length l = 30mm x plate width w
= 28 mm x plate thickness t = 0.2 mm, and both were made of 6 nylon. The size of the piezoelectric vibrator 1 of Comparative Examples a to c is L=25
mm×40=50mm×T×0.6mm, L=25mm×W=40mm
x T x 0.6 mm, L = 40 mm x W = 16 mm x T = 0.53, and the size of the vibrating blade plate is, in the case of comparative example a (Figure 3), length l ₁ = 32 mm x plate width w ₁ = 20 mm. × plate thickness t ₁ = 0.2
mm (vibration blade plate 15a for 50Hz) and length l ₂ = 28mm
x Plate width w ₂ = 20 mm x Plate thickness t ₁ = 0.2 mm (vibration blade plate 15b for 60Hz) made of nylon 6, Comparative example b (No. 4
In the case of (Fig.), length l ₀ = 30 mm x board width w ₀ = 40 mm x board thickness
t ₀ = 0.1 mm (vibrating vane plate 15) made of phosphor bronze, in the case of comparative example c (Fig. 4), length l ₀ = 30 mm x plate width w ₀
= 40mm x plate thickness t ₀ = 0.2mm (vibrating blade plate 15) = 6
Made of nylon. In addition, in FIGS. 3 and 4, 14 indicates a connecting member.

【table】

[Table] In the case of this embodiment A and comparative examples a to c, the vibrating blade plates 15a, 15b, 15 as shown in FIG.
In front of the inner length d = 42 mm square x effective cylinder length D = 110
A wind cylinder 16 with a size of mm, in the case of this embodiment B, a size of d = 62 mm square x effective cylinder length D = 110 mm is provided,
The wind speed when changing the environmental temperature from 15℃ to 0℃ using a refrigerator and driving at a frequency of 50Hz and 60Hz,
Anemometer manufactured by Nihon Kagaku Kogyo (ANEMO MASTER)
MODEL 6141) at point P at the exit of the wind cylinder 16, and converted it into an air volume. As is clear from Table 1 above, the small fan at the destination (comparative example) decreases in temperature.
From the above equation (1), the Young's modulus E increases and the resonance frequency
f ₀ shifts to the higher frequency side, and at 50Hz it becomes further away from the resonant frequency, and the air volume gradually decreases. On the other hand, at 60 Hz, the air volume approaches the resonant frequency, and the air volume increases once, but as it becomes lower, the piezoelectric constant of the piezoelectric vibrator decreases and the vibrating vane loses its bending, and it gradually decreases. Although a decrease in air volume due to a decrease in the piezoelectric constant and the bending of the vibrating vane is unavoidable, the decrease in air volume can be dramatically suppressed. As described above, according to the present invention, one end of the piezoelectric vibrator 1 is fixed to the support part, and the displacement amplifying vibrating vanes 13a and 13b are attached side by side to the other end of the piezoelectric vibrator 1, and each displacement is Expansion vibrating blade plate 13
vibrating blade plates 15a, 15b are attached to a, 13b, and the one set of vibrating blade plates 13a, 15
full length of a and the other set of vibrating blade plates 13b, 15b
If the total length of each vibrating blade plate 15a or 1 is installed individually, it is configured to have a length that resonates at around 50Hz and 60Hz of the power frequency.
5b is resonating, the other vibrating blade plate 15b
Alternatively, since the parts 15a vibrate in synchronization, it is possible not only to drive with a commercial power supply of 50 Hz or 60 Hz, but also to suppress fluctuations in air volume to an extremely small level even when the environmental temperature changes.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the small fan of the present invention, FIG. 2 is a side view thereof, and FIGS. 3 and 4 are front views and FIGS. FIG. 5 is an explanatory diagram showing the wind speed measurement state of the present example and the comparative example. 1... Piezoelectric vibrator, 10... Support member, 12...
... Connection member, 13a, 13b... Vibration vane plate for displacement expansion, 14a, 14b... Connection member, 15a,
15b... vibrating vane plate.

Claims (1)

[Claims] 1 One end of the piezoelectric vibrator is fixed to the support part, a plurality of displacement amplifying vibrating vanes are attached to the other end of the piezoelectric vibrator, and a vibrating vane is attached to the tip of each displacement amplifying vibrating vane. This small fan is characterized by having different resonance frequencies for each vibrating blade.